How do I know on which profile a CMDI file is based?

The MdProfile element (in the Header section) contains a unique profile code (e.g.: Alternatively you can also find the profile identifier as part of the schema location, for example ( 1.1):

<CMD ... xsi:schemaLocation="">

or (CMDI  1.2):

<cmd:CMD ... xsi:schemaLocation="">

You can find the profile in the component registry with the following URL: